LAUSR

BACKGROUND Phytophthora. infestans is a late blight-causing oomycetes pathogen. It evolves and adapts to the host background and new fungicide molecules rapidly within a few years of their release, most likely due to the predominance of transposable elements in its genome. Frequent applications of fungicides cause environmental concerns. Here we developed to target specific RNA interference-based molecules, along with nano clay carriers, that when sprayed on plants are capable of effectively reducing the late blight infection. RESULTS Targeted the genes which are unique to sporulation, early-stage infection, and metabolism pathway, based on our microarray expression data. Used nano clay as a carrier for the SDH, EF-1α, GPI-HAM344, PLD-3, and HSP-90 double-stranded molecule (dsRNA), which were assessed by culture bioassay, detached leaf assay, and spray methods, revealed the reduction in growth, sporulation, and symptom expression. The multiple genes targeted dsRNA nano clay sprayed plants showed enhanced disease resistance (4% disease severity) and least sporulation (<1x103 ), compared to naked dsRNA spray. CONCLUSION The use of nano clay with multi-gene targeted dsRNA was assumed to be involved in the effective delivery, protection and boosting the action of RNAi as Spray induced gene silencing approach (SIGS). A significant reduction in growth, sporulation, disease severity, and decreased expression of the genes authenticates the effects of SIGS on late blight progression. This study demonstrated as a proof of concept of the dsRNA nano clay SIGS approach, which could be an alternative to chemical fungicides and transgenic approaches, for developing a novel plant protection strategy for late blight in an environmentally friendly manner. This article is protected by copyright. All rights reserved.